If Tristan Cooper’s whiplash-inducing hit against Oregon gave you a sense of déjà vu, you weren’t alone.

The Arizona safety’s violent shoulder shot to the chest of Ducks receiver Dillon Mitchell on Saturday bore a striking resemblance to another tackle delivered by a UA defensive back.

In an October 2015 game at Arizona Stadium — on the same side of the 50-yard line — Will Parks buried his right shoulder into the chest of Oregon State receiver Jordan Villamin. Like Mitchell, Villamin was running a crossing route. Like Mitchell, Villamin lost the ball and crumpled to the turf. Neither wideout saw what was coming.

Cooper knew all about Parks. He had seen video of that hit and had studied Parks’ game. The El Paso, Texas, product could see himself in a similar role at Arizona.

That’s debatable. Arizona was leading Oregon 30-8 when Cooper flattened Mitchell in the third quarter. The hit was the signature defensive play on a night when the Wildcats tackled exceptionally well and held the Ducks to a season-low 15 points. Arizona hopes to duplicate that effort Friday night against Colorado.

Cooper recalled a conversation with fellow safety Scottie Young Jr. about the play.

“Man, that’s the one hit every college football player fantasizes about, and you got it,” Young told Cooper. “I was so hyped for you. I think I was more excited than you were.”

Cooper was plenty excited about it; three days later, he could recall every detail of the play.

Arizona was in a cover-2 defense. Cooper hadn’t carried out his responsibilities in a similar circumstance against Oregon State earlier this season and was determined to get it right this time.

After rerouting another receiver who ran upfield from the left slot, Cooper squatted in his zone just inside the 45-yard line. He took a peek to the back side of the play, as defensive coordinator Marcel Yates had instructed.

Cooper didn’t think Oregon quarterback Justin Herbert would throw to Mitchell, who was crossing the field at the 40-yard line from the right side of the formation.

“He lobbed it up, and I was like, ‘Oh dang, this is bad,’ ” Cooper said. “I didn’t want the pick. I didn’t want the touchdown. I just wanted the hit. This was the best receiver that everybody was talking about. If I take him out, it’ll be great.

“Hopefully he’s OK now. I didn’t know I hurt him. Hopefully he’s good and ready to go for this week. I wanted to make him feel the hit.”

Mitchell, the Ducks’ leading receiver, ended up in the concussion protocol. But it wasn’t because Cooper hit him in the head. As UA coach Kevin Sumlin said of the hit, it was “physical football but also clean football.”

Cooper was conscious of avoiding Arizona’s first targeting penalty of the season as the play was unfolding. Safeties coach John Rushing always reminds his players to “never lead with the crown of our helmet,” Cooper said. “When we do drills, any hitting drills, he’s like, ‘Keep your head up. See what you hit.’”

Cooper rewarded Rushing’s faith in him with perhaps his best game of the season. The junior returned to the starting lineup for the first time since Week 4. Cooper had started the opener before being bumped to the second team.

Tackling Tate

No one saw Khalil Tate coming last year against Colorado — least of all the Buffaloes.

Tate came off the bench in the first quarter after starter Brandon Dawkins got hurt and set Boulder’s Folsom Field aflame. Tate rushed for 327 yards, an FBS record for quarterbacks, and four touchdowns. He also completed 12 of 13 passes for 154 yards and a score in Arizona’s 45-42 victory.

Colorado will be ready this time. Tate hasn’t run nearly as much this season while battling an ankle injury and adjusting to a new system. He’ll have the Buffs’ full attention nonetheless.

“I just hope we can tackle him in space,” Colorado coach Mike MacIntyre said. “We couldn’t tackle him in space last year. We know where he is now. We have a better understanding of what they’re trying to do with him. He’s a phenomenal athlete.”

MacIntyre acknowledged that the offense has changed with Sumlin and Noel Mazzone running the show. MacIntyre also noted that Arizona was “really explosive” against Oregon, “which has a really good defense.” Tate looked faster and smoother than he has at any point this season.

“They’re utilizing him in a good way,” MacIntyre said, “and their offense is clicking.”

Multipurpose Montez

The Wildcats consistently confounded and harassed Herbert, who had his worst game of the season.

Like Herbert, Colorado redshirt junior Steven Montez is big (6-5, 230) and athletic. He had 81 rushing yards and two touchdowns against UCLA and 66 yards against Oregon State.

“Getting a lot of hats to the ball is going to be very helpful,” said Cooper, who faced Montez in high school. “One dude might not be able to take him down.”

But Montez has grown the most as a passer, especially when it comes to the mental side of the discipline.

“Being able to read defenses, understand protections really well and know where he’s going with the ball — that, to me, is where he’s made a big, big stride,” MacIntyre said.

Working with first-year QB coach Kurt Roper, Montez has raised his completion percentage from 60.5 last year to 68.2 this year. He had a 2-to-1 touchdown-to-interception ratio (18-9); now it’s 3.5-to-1 (14-4).

Montez ranks fourth in the Pac-12 in passing yards per game (256.6) and efficiency rating (147.1). Colorado ranks third in scoring (32.0 ppg).